CN1840719A

CN1840719A - Composition, product, and manufacturing method of superalloy

Info

Publication number: CN1840719A
Application number: CNA2006100592457A
Authority: CN
Inventors: P·L·雷诺
Original assignee: United Technologies Corp
Current assignee: RTX Corp
Priority date: 2005-03-30
Filing date: 2006-01-28
Publication date: 2006-10-04
Also published as: US20100008790A1; US8147749B2; CA2533574A1; KR20060106635A; EP1710322B1; AU2006200325A1; US20100158695A1; SG126026A1; KR20070114689A; KR100810838B1; EP1710322A1; TW200639260A; JP2006283186A; JP4498282B2

Abstract

A composition of matter comprises, in combination, in weight percent: a largest content of nickel; at least 16.0 percent cobalt; and at least 3.0 percent tantalum. The composition may be used in power metallurgical processes to form turbine engine turbine disks.

Description

Superalloy composition, goods, and manufacture method

U.S. the right of government

The present invention is based on No.N00421-02-3-3111 agreement that headquarters of air force-navy authorize, finishes under the support of United States Government.United States Government has some right to the present invention.

Technical background

The present invention relates to nickel-base heat resisting superalloy (superalloy).Especially, the present invention relates to be used for this class superalloy of high-temperature fuel gas turbine engine components such as turbine wheel (disk) and compressor impeller.

The burning of gas turbine engine, turbine and exhaust gas region will bear extreme heating as the compressor latter half.This heating has brought serious materials limitations to these regional parts.A zone that is even more important comprises the blade bearing turbine wheel.In the most of the time of engine operation, impeller also bears extreme mechanical stress except bearing above-mentioned thermal stresses.

Developed exotic materials to satisfy needs in the turbine wheel application facet.United States Patent (USP) 6521175 discloses a kind of senior nickel-base heat resisting superalloy of producing turbine wheel by powder metallurgy.The content of ' 175 patent disclosure is incorporated herein by reference as elaborating.' 175 patent disclosure be the optimized impeller alloy of short period of time engine cycle, its impeller temperature is approximate to be approximately 1500 °F (816 ℃).At US5104614, US2004221927 discloses other impeller alloy among EP1201777 and the EP1195446.

Proposed to satisfy the application of turbine blade respectively with other material.Blade is generally made by casting, and some blades have complex inner structure.United States Patent (USP) 3061426,4209348,4569824,4719080,5270123,6355117 discloses different blade alloys with 6706241.

Summary of the invention

One aspect of the present invention relates to a kind of Ni-based composition (composition) material, and it has the tantalum of higher concentration and one or more other compositions of higher concentration.

In a different manner, alloy can be used for producing turbine wheel by powder metallurgical technique.Described one or more other compositions can comprise cobalt.Described one or more other compositions can comprise that γ casts aside the combination (combination) of forming element (γ ') and/or η forming element (η).

The details of one or more embodiments of the present invention will be set forth in accompanying drawing and the following description.Other features of the present invention, purpose and advantage will become apparent by specification sheets and accompanying drawing and by claims.

Description of drawings

Fig. 1 is the partial exploded view of gas-turbine unit turbine impeller assembly.

Fig. 2 is a process flow sheet of making impeller in the assembly shown in Figure 1.

Fig. 3 is the table of the composition of invention impeller alloy and prior art alloy.

Fig. 4 is the light micrograph after the impeller alloy corrosion shown in Figure 3.

Fig. 5 is the scanning electron microscope Photomicrograph (SEM) after the impeller alloy corrosion shown in Figure 3.

Form shown in Figure 6 is the selection measurement characteristics of impeller alloy shown in Figure 3 and prior art alloy.

Same reference numerals in different accompanying drawings is represented components identical.

Describe in detail

Figure 1 shows that gas turbine engine impeller assembly 20, comprise impeller 22 and a plurality of blade 24.Impeller is generally annular, extends to outer rim 28 from the bore hole or the wheel hub 26 of the inboard that is positioned at central hole.It between bore hole 26 and wheel rim 28 relatively thin radially disc 30.The outer complementary portion 34 that is with the engagement part 32 (for example, dovetail-indent) of row's annular array with engagement blade 24 of wheel rim 28.In other embodiments, impeller and blade can be the structures (for example, so-called " integral leaf chip " rotor or impeller) of an integral body.

Impeller 22 is (for example: disclosed in United States Patent (USP) 6521175) that has superiority by the manufacturing of p/m forging technology.Fig. 2 has shown a kind of typical technology.The basal component of hybrid alloys (for example, with the single component of refining purity or the form of its alloy).Fully molten mixture is to eliminate component segregation.The mixture of atomized molten is to form the melt metal drop.The drop cooled and solidified powdered particle of atomizing.Can sieve the powder size scope that powder is allowed with restriction.Powder is put into container.Powder container is by relating to the rapid technology compacting of multistep of compression and heating.Subsequently, the powder of the compacting of gained has the true density of this alloy basically, and the typical chemical segregation of big foundry goods can not occur.The blank of compacted powder can forge the forging that becomes to have the impeller elementary contour in suitable temperature and deformation range.After this, forging is through comprising that heat is cooled off subsequently fast or the rapid technology of multistep of quenching is heat-treated.Preferably, thermal treatment with feature gamma (γ) particle diameter from typical 10 μ m or be increased to typical 20-120 μ m (preferred 30-60 μ m) more for a short time.Quenching in the thermal treatment can form also that ideal dimensions distributes and the reinforced deposition of volume percent (for example: gamma left-falling stroke (γ ') and eta (η) further go through mutually below).Subsequently, change these distribution situations to produce the necessary mechanical property of making of forging with thermal treatment.The particle diameter that increases and the forging of processing good high-temperature creep resistance and low progress of fracture speed during use is relevant.Subsequently to carry out the processing (machine) of final profile and groove through heat treated forging.

Although typical modern impeller alloy composition comprises the tantalum (Ta) of 0-3 weight percent, alloy of the present invention has higher contents level.Think that this contents level of Ta is unique in the impeller alloy.Especially, think that the Ta that is higher than 3% level is unique in conjunction with other the γ ' forming element (that is aluminium (Al), titanium (Ti), niobium (Nb), a kind of or combination in tungsten (W) and the hafnium (Hf)) and the cobalt (Co) of higher level of last higher level.Ta is as γ ' and γ sosoloid enhancer additives mutually.The existence of big Ta atom reduced mainly γ ' mutually in generation but also occur in the diffusion of γ in mutually.This can reduce high temperature creep.Further go through the following examples, think also in the alloy of the present invention that Ta content also helps to form η mutually and guarantee that it compares less relatively with γ crystal grain greater than 6%.Therefore, the η precipitation helps precipitation hardening, is similar to the strengthening mechanism that obtains by γ ' precipitated phase.

Compare alloy of the present invention and existing blade alloy valuable equally.The Ta content of existing blade alloy is higher relatively to be very general.Difference on some is formed between alloy of the present invention and the existing blade alloy.Blade alloy is generally produced by casting technique, because its high-temperature behavior is to improve by the ability that forms very big polycrystalline and/or single crystal grain (also claiming monocrystalline).The greatly formation of grain-size and will damage the purposes of this blade alloy in the powder metallurgy application to the requirement of high-temperature heat treatment.Final rate of cooling will cause serious quenching crack and tear (especially for bigger parts).Among other difference, these blade alloys have cobalt (Co) concentration lower than the typical alloy of the present invention.In the broadest sense, with respect to existing high Ta blade alloy, the typical alloy of the present invention customizes at the application in the impeller manufacturing by regulating other element, and other element comprises Al, Co, Cr, Hf, Mo, Nb, one or more among Ti and the W.Yet, can not get rid of the application possibility of alloy of the present invention at blade, wheel blade and other non-wheel member.

Therefore, make optimized being still within the bounds of possibility of high Ta impeller alloy (for example: under 1200-1500  (649-816 ℃) or higher temperature, use) of high-temperature behavior with improvement.Note, in any place that has provided metric system and English unit simultaneously, metric system be from English system be converted to (for example: the tolerance of Britain) and to should not be considered as metric system be the expression trueness error.

Embodiment

The Table I of Fig. 3 is depicted as the specification of an a kind of exemplary alloy or a class alloy.Nominal is formed and scope is based on (for example: derive) that the sensitivity of element variation is derived from phasor.This table also demonstrates the measurement of test sample and forms.The nominal that this table also demonstrates among existing technology alloy NF3 and the ME16 is formed (for example: open in US6521175 and EP1195446 respectively).Express unless have, all content are all represented with weight, particularly are weight percents.

Most basic η form is Ni ₃Ti.It has been generally acknowledged that, in existing impeller and blade alloy, when the weight ratio of Al and Ti is less than or equal to 1, form η.In exemplary alloy, this ratio is greater than 1.The compositional analysis of η phase shows, and Ni ₃(Ti, Ta) the same, Ta also helps to form the η phase very much.Therefore, different mutual relationships (being not only the relation of performance Al and Ti) may be more suitable.Utilize the standard profile coefficient can estimate replacement usually by the total molar fraction of element (as atomic percent) of the occupied atom site of Al.These elements comprise Hf, Mo, Nb, Ta, Ti, V, W and less Cr.These elements are as the solution strengthening agent of γ ' phase.As γ ' Xiang Zhongyou too much during these adatoms, be easy to form other phase, for example when containing too much Ti, be easy to form η.Therefore, the ratio with Al and these other element total amounts is useful as the predictor that forms η.For example, when being less than or equal to about 0.79-0.81 with the mol ratio that is distributed to other atom total amount of the Al position in γ ', the Al atom forms η.This situation at high Ta content is effective especially.Nominally, for this ratio of NF3 be 0.84 and the weight percent of Al and Ti be 1.0.Be respectively 0.82 and 0.968 for the above-mentioned value of NF3 test sample.Can dope with the Ti ratio according to the Al of routine and to have η among the NF3 mutually, but not observe its existence.ME16 has similar rated value 0.85 and 0.98 respectively, does not also exist the η that dopes by Al and Ti ratio mutually.

Therefore, be sure of that the formation of η and quality thereof are very sensitive to the content of Ti and Ta.If Al reaches above-mentioned definite ratio with the ratio of its substitute element, can further indicate the formation of η so approx.According to estimates, if the content of Al is less than or equal to about 3.5, Ta content is more than or equal to about 6.35%, Co content is more than or equal to about 16%, Ti content is more than or equal to about 2.25%, and, perhaps most important, the total content of Ti and Ta will form η so more than or equal to about 8.0%.

Except replacing the forming element of Ti as η, Ta has special influence aspect the sedimentary size of control η.Ta and Ti are at least about 3 content ratio and can effectively control the sedimentary size of η and reach mechanical property preferably.

Fig. 4 and Fig. 5 have shown the microtexture that sample is formed, reflect atomize extremely about 74 μ m (0.0029 inch) and the more powder of small particle size, suppress subsequently, forge and quench 1182 ℃ of (2160 ) thermal treatments two hours and with the speed of 0.93-1.39 ℃/s (56-83 ℃ of part (100-150  part)).Fig. 4 has shown η precipitation 100, and it is represented with light tone in γ matrix 102.Proximate grain-size is 30 μ m.Fig. 5 has shown matrix 102, and it comprises the much smaller γ ' precipitation 104 in the γ matrix 106.It is even substantially that these micrograms demonstrate the distribution of η phase.η is not more than the γ particle diameter mutually can not produce harmful effect to cycle performance so that can be used as strengthening phase, if η is mutually excessive this harmful effect can take place.

Fig. 5 has shown the sedimentary homogeneity of γ '.These precipitations and be distributed with and help precipitation strength.Can control the degree and the characteristic of precipitation strength by controlling sedimentary size (alligatoring) and spacing.In addition, along the η interface be then unconventional/linable less γ ' precipitation zone 108.These zones 108 can further hinder the dislocation motion.This obstruction is the integral part that prevents the reinforcement of time dependent deformation such as creep.The uniform distribution of γ ' and tiny particle diameter show that it is to form under far below the transient temperature during quenching in zone 108.

It has been generally acknowledged that the alloy welding difficulty that γ ' content is high.This difficulty is owing to alloy causes from welding (interim fusion) cooling suddenly.The unexpected cooling of high γ ' alloy causes cracking in the very big internal stress of the inner formation of alloy.

The special η precipitation of an amplification has a kind of built-in carbide precipitation 120 among Fig. 5.Carbide mainly is titanium carbide and/or the tantalum carbide that forms at the powder particle solidificating period, is the normal by product when having carbon.Yet carbon can be strengthened crystal boundary and avoid fragility.This carbide particle has extremely low volume fraction, and is high very stable because of its fusing point, and it is believed that it does not have obvious influence to alloy property.

As mentioned above, exist the η of certain particle diameter can provide additional hardening mutually, its particle diameter is enough little little simultaneously to producing harm to help precipitated phase to strengthen.If η extends through two (or more) crystal grain mutually, the living dislocation of these two grain shaped sells of one's property will not only add up so, thereby have very large harm (especially in recurrent state).Typical η is deposited in 0.2 μ m Quench γ and encloses in the thing with median size 30-45 μ m (for γ) long for about 2-14 μ m.This size is near the sedimentary size of finding in conventional sintered alloy such as IN100 and ME16 of big γ '.Test up to now shows do not have harmful consequences (for example: do not have the loss in notch diuctility and disrumpent feelings life-span).

Table II among Fig. 6 has shown the mechanical property that exemplary alloy and prior art alloy are selected.Three kinds of alloys all obtain nominal ASTM6.5 particle diameter (the about 37.8 μ m (0.0015inch) of diameter) by thermal treatment.All data all are (that is: heat-treat more than γ ' solvus producing identical particle diameter, and with identical speed cooling) that obtains from the diffusion oxide material of similar processing.Data show that the improvement of alloy of the present invention aspect anti-quenching crack is the most remarkable.Be sure of that the fine and closely woven distribution of γ ' in the zone 108 around the η precipitation has participated in improving anti-quenching crack (could form γ ' precipitation up to reaching low-down temperature in the cycle period of quenching).Lacking this γ ' meeting around the η promoted stress to distribute again and finally causes ftractureing in the cycle period of quenching.

As can be seen, for the particle diameter of equivalence, the temporal correlation (creep and fracture) that sample is formed, yield strength and final tensile strength are significantly improved under 816 ℃ (1500 ) from Table II.The yield strength ratio NF3 that sample is formed under 732 ℃ of (1350 ) temperature is low slightly, but still significantly is better than ME16.These character can be by further composition and technology adjustment obtain further to improve.

Designed and be used to assess the test that resists the quenching crack performance mutually, the result under 1093 ℃ (2000 ) also lists in the Table II.This test has illustrated the ability of the anti-stress and strain of estimating (distortion) in the circulation of quenching.Test only relies on the particle diameter and the composition of alloy, and does not rely on speed of cooling and any subsequently processing sequence.Sample is formed at 1093 ℃ (2000 ) has remarkable improvement than two kinds of benchmark compositions.

Have low Ta content and/or lack the sedimentary alternative alloy of η and still may have some excellent high-temperature performances.For example, the low Ta content in 3-6% scope or narrower and small 4-6% scope is possible.For there not being the η alloy substantially, Ti and Ta total content are approximately 5-9%.Other content can be similar to those (therefore having high slightly Ni content) of ideal format.The alloy higher with Ta content is the same, also can distinguish these alloys by high Co content and high Co and Cr total amount.Typically, Co and Cr total amount are at least 26.0% in low Ta alloy, can be similar or wide slightly in high Ta alloy (for example: 20.0% or 22.0%).

One or more embodiments of the present invention have been described.Yet, be appreciated that under the situation that does not exceed the spirit and scope of the present invention and can make different changes.For example, the manipulation require of any non-conventional engine will influence the processing of its parts.As mentioned above, this principle can be used for making as rotor, and spindle unit (for example: hub structure) wait other parts.Therefore, other embodiment is in the scope of accessory claim book.

Claims

1. The composition of a substance, including the following combinations, expressed in weight percent:

maximum nickel content;

At least 16.0% cobalt; and

At least 6.0% tantalum.

2. The composition of claim 1, wherein:

The nickel content is at least 50%.

3. The composition of claim 1, wherein:

The nickel content is 44-56%.

4. The composition of claim 1, wherein:

The nickel content is 48-52%.

5. The composition of claim 1, further comprising:

aluminum composition; and

A titanium component having a ratio of said titanium component to said aluminum component of at least 0.57.

6. The composition of claim 1, further comprising:

aluminum;

titanium; and

Niobium, said total content of tantalum, aluminum, titanium and niobium being at least 12.3%.

7. The composition of claim 1, further comprising:

At least 6.0% chromium.

8. The composition of claim 7, further comprising:

At least 2.5% aluminum; and

If there are additional ingredients, each additional ingredient does not exceed 4.0% each.

9. The composition of claim 7, further comprising:

One or more of aluminum, titanium, niobium and hafnium in a total amount of at least 5.8%.

10. The composition of claim 7, further comprising:

One or more of aluminum, titanium, niobium and hafnium in a total amount of at least 6.5%.

11. The composition of claim 1, further comprising:

At least 2.5% aluminum.

12. The composition of claim 11, further comprising:

At least 1.5% titanium.

13. The composition of claim 1, further comprising:

At least 1.5% titanium.

14. The composition of claim 1, further comprising:

At least 1.5% tungsten.

15. The composition of claim 1, further comprising:

At least 0.5% niobium.

16. The composition of claim 1 in powder form.

17. A method of forming an article comprising:

compacting a powder having the composition of claim 1;

the compacted powder is forged to form the precursor; and

The forged precursor is processed.

18. The method of claim 17, further comprising:

The precursor is thermally treated by heating to no more than 1232°C (2250°F) before and at least once after processing.

19. The method of claim 17, further comprising:

At least once before and after processing, the precursor is thermally treated effective to increase the characteristic gamma particle size from a first value of about 10 μm or less to a second value of 20-120 μm.

20. A turbine or compressor wheel of a gas turbine engine having the composition as claimed in claim 1.

21. A composition of matter comprising the following combinations, expressed in weight percent:

maximum nickel content;

A total of at least 20.0% cobalt and chromium; and

At least 6.0% tantalum.

22. The composition of claim 21 further comprising:

23. A method of forming an article comprising:

compacting a powder having the composition of claim 21;

the compacted powder is forged to form the precursor; and

The forged precursor is processed.

24. A composition of matter, comprising a combination of the following components, expressed in weight percent:

about 18.0% to about 21.0% cobalt, about 8.5% to about 11.0% chromium, about 6.5% to about 8.5% tantalum, about 2.2% to about 2.75% tungsten, about 2.5% to about 3.4% molybdenum, about 0.03% to about 0.7% zirconium, about 0.8% to about 2.0% niobium, about 2.0% to about 2.75% titanium, about 3.0% to about 3.5% aluminum, about 0.02% to about 0.07% carbon, about 0.02% to about 0.06% boron; and

The balance of nickel and a small amount of impurities.

25. Composition of matter as claimed in claim 24 for use in the manufacture of turbine wheels.

26. A gas turbine engine impeller or impeller substrate comprising a combination of the following, expressed in weight percent:

maximum nickel content;

At least 16.0% cobalt; and

At least 6.0% tantalum.

27. A composition of matter comprising a combination of the following, expressed in weight percent:

maximum nickel content;

at least 16.0% cobalt;

a total content of at least 26.0% cobalt and chromium, and

At least 3.0% tantalum.

28. A turbine or compressor wheel of a gas turbine engine having the composition as claimed in claim 27.

29. A turbine or compressor impeller for a gas turbine engine as claimed in claim 28 which is one of:

Integral blade impellers, in which the blades are integrated into the impeller body; and

An impeller with an annular arrangement of blade connecting parts.